How to get more speed for the blade
Note - this Blend file was from Version 2.77a.   The same principle applies for later versions.



Once the rotation is set up, it often looks more convincing to fade in a semmi-transparent disc whilst also fading out the propeller to semmi- transparency, reversing the procedure as it slows down.

In this example the Material slot's 'Alpha' slider was keyframed for both the prop &amp; disc.

Layer 2 is a turbine propeller whereas Layer 7 is a piston engine with compression.  The compression kick-back is done in the graph editor.
(see the green 'Y rotation' f-curve where the prop stops)